Group fairness metrics are an established way of assessing the fairness of prediction-based decision-making systems. However, these metrics are still insufficiently linked to philosophical theories, and their moral meaning is often unclear. In this paper, we propose a comprehensive framework for group fairness metrics, which links them to more theories of distributive justice. The different group fairness metrics differ in their choices about how to measure the benefit or harm of a decision for the affected individuals, and what moral claims to benefits are assumed. Our unifying framework reveals the normative choices associated with standard group fairness metrics and allows an interpretation of their moral substance. In addition, this broader view provides a structure for the expansion of standard fairness metrics that we find in the literature. This expansion allows addressing several criticisms of standard group fairness metrics, specifically: (1) they are parity-based, i.e., they demand some form of equality between groups, which may sometimes be detrimental to marginalized groups; (2) they only compare decisions across groups but not the resulting consequences for these groups; and (3) the full breadth of the distributive justice literature is not sufficiently represented.

翻译：群体公平度量是评估基于预测的决策系统公平性的一种成熟方法。然而，这些度量与哲学理论的关联仍不充分，其道德含义常常模糊不清。本文提出一个针对群体公平度量的综合框架，将其与更多分配正义理论联系起来。不同的群体公平度量在衡量决策对受影响的个体带来的益处或损害的方式上存在差异，并且对利益所依据的道德主张的假设也有所不同。我们的统一框架揭示了标准群体公平度量相关的规范性选择，并允许对其道德实质进行诠释。此外，这一更广阔的视角为文献中现有的标准公平度量的扩展提供了结构。这种扩展得以回应针对标准群体公平度量的若干批评，具体包括：（1）它们基于均等原则，即要求群体间某种形式的平等，这在某些情况下可能对边缘化群体不利；（2）它们仅比较不同群体间的决策，而非这些决策对这些群体产生的后果；（3）分配正义文献的完整广度未得到充分体现。